A method and device for transferring images to different sides of a receiving sheet are known. For Example, in European Patent Application 0,222,224, images are placed on opposite sides of the support for transfer to different sides of a receiving sheet. In U.S. Pat. No. 3,672,765, on the other hand, images are transferred from the same side of the support and placed on the opposite sides of the receiving sheet in seriatim.
Another method and device are disclosed in the journal Research Disclosure of November 1984, No. 24708. In this device the leading image of two images situated on a photoconductive belt advanced by a transport roller is transferred, in an image transfer zone, to a first image transfer roller brought into rolling contact with the photoconductive belt. The image is then transferred to a second image transfer roller brought into rolling contact with the first image transfer roller. The first image transfer roller is then moved away and the second image transfer roller is brought into rolling contact with the photoconductive belt in the image transfer zone. A receiving sheet is then fed through the image transfer zone for transfer of the leading image from the second image transfer roller to one side of the receiving sheet and simultaneously therewith the transfer of the trailing image of the two images on the photoconductive belt from the latter directly to the other side of the receiving sheet.
The image on one side of the receiving sheet has thus undergone two image transfer steps more than the image on the other side of the receiving sheet. Since each image transfer step is accompanied by a loss of image quality, there is, therefore, a difference in quality between the images transferred to the different sides of the receiving sheet. This device also has the disadvantage that because the image transfer which takes place is always incomplete, the two image transfer rollers have to be repeatedly cleaned, in addition to the photoconductive belt, to prevent transfer of a ghost image to a following receiving sheet.
Accordingly, it is an object of the present invention to provide a method and device without these disadvantages.